The International Union of Soil Sciences (IUSS) is the global union of soil scientists. The objectives of the IUSS are to promote all branches of soil science, and to support all soil scientists across the world in the pursuit of their activities. This website provides information for IUSS members and those interested in soil science.

Division 1 – Soils in Space and Time

COMMISSION 1.1 – Soil morphology and micromorphology

Soil is a continuous natural body that has spatial and temporal dimensions (soil cover or pedosphere). Primary organic and inorganic constituents are organized into secondary polyhedral structural units that in turn are assembled into vertical and lateral horizons that comprise soils unique to the environment in which they are formed. The morphogenetic properties that comprise soils are the essential elements of soil classification, interpretation, and land quality. They result from current and paleohistory of soil environments and in turn record many of the environmental signatures that result. Morphogenetic properties are dynamic and anisotrophic in response to other state factor perturbations. The study of the soil cover structures develops knowledge about soil properties and dynamics; it permits the understanding of the genesis of the soil covers.

COMMISSION 1.2 – Soil geography

Soil geography is the study of the soil cover and its many morphogenetic attributes as a function of climate, geology, relief, vegetation, human activities, and history (natural and anthropogenic). It is that component of the Division that serves as a vehicle to transfer soil knowledge gained in C 1.1, especially as it impacts ecosystem sustainability, food security, land carrying capacity, human health, and the global biosphere. Different types of maps, at different scales, represent soil distribution covers of significance to the aforementioned utilitarian priorities and the field of soil science as a whole.

COMMISSION 1.3 – Soil Genesis

This Commission quantifies the fundamental physical, chemical, biological, and mineralogical processes (pedogenic) of gains, losses, translocations, and transformations occurring in soils from micro to macro scales to explain and understand profile formation. It utilizes fundamental knowledge gained from other disciplines to model dynamics and processes responsible for soil behavior at the landscape or ecological scale. This information is integrated with that of other scientific databases to quantify environmental interactions under which soils formed in both modern and paleo times.

COMMISSION 1.4 – Soil classification

Soil classification is that Commission within the division that categorizes the infinite number of morphogenetic attributes of the pedoshpere so that the attributes used to classify soils permit the greatest number, most precise, and most significant statements about soil behavior and genesis. Classification systems are hierarchical so the knowledge base and interpretational inferences become more specific from the higher categories to lower ones. Taxonomic names are given to the categories and constituent classes so the relationships between soil attributes (horizons, pedon(s), cartographic units, generalized soil associations, soil covers, etc.) can best be remembered for a specific objective. Classification allows scientists to communicate and share knowledge about the ‘body that soil scientists study.

COMMISSION 1.5 – Pedometrics

By pedometrics the Commission means the application of mathematical and statistical methods for the study of the distribution and genesis of soils. The goal of pedometrics is to achieve a better understanding of the soil as a phenomenon that varies over different scales in space and time. This understanding is important, both for improved soil management and for our scientific appreciation of the soil and the systems (agronomic, ecological and hydrological) of which it is a part. For this reason much of pedometrics is concerned with predicting the properties of the soil in space and time, with sampling and monitoring the soil and with modelling the soil’s behaviour. Pedometricians are typically engaged in developing and applying quantitative methods to apply to these problems. These include geostatistical methods for spatial prediction, sampling designs and strategies, linear modelling methods and novel mathematical and computational techniques such as wavelet transforms, data mining and fuzzy logic.

COMMISSION 1.6 – Paleopedology

The mission of the Palaeopedology Commission is to promote cooperative research by Soil and Environmental Scientists and Quaternary Geologists to increase our knowledge of past environments derived from paleosols. In general, paleosols are recognized as soils which have formed under different environmental conditions (in particular climate and vegetation) from those of present day. The study of paleosols is a multi-disciplinary activity, which includes, in addition to Soil Sciences, Earth, Environmental, and Human Sciences. The issues covered by Paleopedology encompass the understanding of soil forming processes, deep weathering and regolith formation, soil mapping, soil conservation, Quaternary geology, geological mapping, neotectonics, and pedoarcheology. The method is to compare the properties of dated paleosols and paleosol sequences with those of modern soils that are related to the known climate and other environmental factors as a proxy for interpreting past climatic and ecological changes and hence predicting soil changes over time. The motto of the Commission is rerum cognoscere causas (to know the cause of things).

Division 2 – Soil properties and processes

COMMISSION 2.1 – Soil physics

Soil physics deals with the physical properties of the soil, with emphasis on transport of matter and energy. Major research thrusts include modeling transport of inorganic, organic and microbial contaminants, fractal mathematics, spatial variability, geostatistics, computer-assisted tomography, and remote sensing of soil physical properties.

COMMISSION 2.4 – Soil mineralogy

Soil Mineralogy deals with all kinds of minerals occurring in soil environments especially rockborne and soilborne ones. Important soil processes like weathering and mineral neo-formation are major tasks. The consequences of transport and biological turnover on minerals and their relevance to soil micro- and macro-structure is studied. The relevance of soil minerals and mineral-organic interactions are taken into account in relation to environmental and specifically soil fertility issues. Specific attention is given to the use of advanced analytical techniques to analyze mineral crystal structure, surface properties, and mineral-mineral as well as mineral-organic components interactions from the molecular scale up to the consequence for the landscape level.

The Commission deals with abiotic and biotic interactive processes occurring in soil with the goal of advancing the understanding on physical/chemical/biological interfacial systems at the molecular to field/landscape levels. Major research thrusts include: (1) mineral and biological catalysis and enzyme-mineral interactions leading to humus and organo-mineral complex formation, (2) surface reactions of micro- and macro-biota and biomolecules with soil particles, (3) the effect of soil abiotic and biotic interactive processes on the structure, dynamics, and activities of microbial communities, and (4) ecological impacts of soil abiotic and biotic interactive processes on (a) porosity formation by structure or organization development and on (b) biogeochemical transformation and transport of chemical and biological components at different spatial and temporal scales.

Division 3 – Soil Use and Management

COMMISSION 3.1 – Soil evaluation and land use planning

As soil is increasingly acknowledged as a scarce and finite resource it is essential that decisions related to soil(s) use(s) are optimized taking account of the nature and pattern of the soil and the socio-economic conditions at a variety of scales. Activities of this Commission will encompass the broad activities of soil evaluation and land use planning and will include related activities of data gathering and management including remote sensing and Geographical Information Systems.

COMMISSION 3.2 – Soil and water conservation

This Commission acknowledges that an essential element in many soil management strategies is the need to maintain the quality of the soil resource through appropriate soil and land management practices, including tillage. Frequently, the conservation of soil is intimately coupled with the management of surface waters through erosion control. In addition to the prevention of erosion by water and wind, this Commission will also concern itself with the efficient management of soil water through irrigation, drainage and the limitation of water loss from the soil surface.

COMMISSION 3.3 – Soil fertility and plant Nutrition

The management of soil fertility is a major activity of a substantial proportion of the world’s soil scientists. The inclusion of plant nutrition in the title of this Commission recognizes the often very close relationship between those managing soil fertility and those concerned directly with plant nutrition. This Commission would concern itself with the identification of technologies appropriate to the particular soil conditions and combinations of soil conditions.

COMMISSION 3.4 – Soil engineering and Technology

This Commission is concerned with engineering uses of soils both in the agriculture and non-agriculture context. Soils serve many purposes such as road beds and fill material, they are shaped and changed for many uses, used for filter fields, sewage and waste storage etc.

Many soils of the world are degraded, both because of agricultural activity and through the pollution arising from urban, industrial, and other human activities. The purpose of this Commission is to use our knowledge and understanding of soil properties and processes to ensure that damaged/degraded soils may be remediated or reclaimed and returned to productive use.

COMMISSION 3.6 – Salt-affected Soils

Soil salinization is one of the more subtle and progressive causes of soil degradation, menacing some of the most productive fields under irrigated agriculture. Also it is an increasing environmental concern for those areas in which climate change scenarios predict aridity increase. Salinity is a natural inherent condition of many ecosystems contributing to global biodiversity supporting halophytes.
The Commission of Salt-affected Soils, through the organization of workshops and collaboration with scientific journals, provides a forum for soil scientists whose research focuses on natural saline ecosystems or on secondary salinization. Processes of formation of salt-affected soils, temporal and spatial variation of salinity, modelling of irrigation under risk of salinization, management practices aimed to avoiding or mitigating soil salinization, basic research on chemistry/physics/biology of salt-affected soils, plant ecology of halophytes related to the soil properties, reuse of saline and drainage waters, are among the frequent topics discussed at the Commission meetings.

Division 4 – The Role of Soils in Sustaining Society and the Environment

COMMISSION 4.1 – Soils and the Environment

This Commission will look at the soil as part of the ecosystem. Human activities have a strong impact on the ecosystems and the soil and environment interactions in relation to humans are particularly important. Soils- a major component of the biosphere at the interface between the lithosphere, atmosphere and biosphere – are investigated through several international programs such as IGBP; in the same way, the soil plays a considerable role in the carbon sequestration (UN Convention on Climate Change) and is the habitat for a number of species covered by the Biodiversity Convention.

COMMISSION 4.2 – Soils, food security, and human health

In most countries soils are essential for food production. Considering that one third of the land area is presently used for agriculture, and the world population is increasing, creating additional pressure on agricultural land, providing enough safe and nutritious food will be an ongoing challenge. Among the concerns of this commission, there is the maintenance and conservation of agricultural land, the role of soils in a changing world in relationship to human health.

COMMISSION 4.3 – Soils and land use Change

Soils play a large role as source and sinks of greenhouse gases. In a context of global sustainability, this Commission will investigate how the source/sink function of the soils can be managed and controlled to mitigate the impact of climate change. Of interest to all are significant changes in land use, including the effects of urbanisation, forest conversion and productive land being allocated to other uses. Such change falls under the auspices of Commission 4.3.

COMMISSION 4.4 – Soil education and public awareness

Commission 4.4. deals with teaching methods and the development of soil scientists – but also how soil-related knowledge is presented to other interested parties, as well as the information provided to the public and related general public awareness. A well informed public is needed so that the importance of soils is understood by all.

COMMISSION 4.5 – History, philosophy, and sociology of soil science

This Commission deals with our past; it links the study of what has happened in history and how soils can be used to help explain the past changes. This Commission is not just a record of history but the use and understanding of soil information and its relationship to human development and history.